Liquid crystal display device and back light unit thereof

Abstract

A back light unit adapted to provide light to a liquid crystal display panel includes a housing, at least a light generator, and an optical filter. The light generator is disposed inside the housing for generating white light beams. The optical filter is disposed in an optical path of the white light beams between the light generator and the liquid crystal display panel for filtering the white light beams within a particular wavelength range of visible light. The hue of the white light beams before and after passing through the optical filter are the same.

1 . A back light unit adapted to provide light to a liquid crystal display panel, the back light unit comprising:
 a housing;   at least a light generator disposed inside the housing for generating white light beams; and   an optical filter disposed in an optical path of the white light beams between the light generator and the liquid crystal display panel for filtering the white light beams within a particular wavelength range of visible light, wherein the hue of the white light beams before and after passing through the optical filter are the same.   
   
   
       2 . The back light unit of  claim 1 , wherein the particular wavelength range is between blue light wavelength range and green light wavelength range. 
   
   
       3 . The back light unit of  claim 2 , wherein the particular wavelength range is substantially between 473 nm and 523 nm. 
   
   
       4 . The back light unit of  claim 1 , wherein the particular wavelength range is between green light wavelength range and red light wavelength range. 
   
   
       5 . The back light unit of  claim 4 , wherein the particular wavelength range is substantially between 565 nm and 615 nm. 
   
   
       6 . The back light unit of  claim 1 , wherein the back light unit comprises a light guide plate disposed inside the housing, the at least one light generator is disposed on at least one side of the light guide plate, and the light guide plate has an incident plane where the white light beams enter and an exiting plane where the white light beams exit. 
   
   
       7 . The back light unit of  claim 6 , wherein the optical filter is disposed on the incident plane of the light guide plate. 
   
   
       8 . The back light unit of  claim 6 , wherein the optical filter is disposed on the exiting plane of the light guide plate. 
   
   
       9 . The back light unit of  claim 1 , wherein the at least one light generator disposed right below the liquid crystal display panel. 
   
   
       10 . The back light unit of  claim 1 , wherein the light generator comprises a fluorescent lamp. 
   
   
       11 . The back light unit of  claim 1 , wherein the light generator comprises a light emitting diode device. 
   
   
       12 . The back light unit of  claim 11 , wherein the light emitting diode device comprises an encapsulated layer, and the optical filter is integrated into the encapsulated layer of the light emitting diode device. 
   
   
       13 . A liquid crystal display device, comprising:
 a liquid crystal display panel comprising a color filter; and   a back light unit disposed below the liquid crystal display panel for providing light to the liquid crystal display panel, the back light unit comprising:   a housing;   at least a light generator disposed inside the housing for generating white light beams; and   an optical filter disposed in an optical path of the white light beams between the light generator and the liquid crystal display panel, the optical filter having a particular transmittance with respect to light beams within a particular wavelength range of visible light.   
   
   
       14 . The liquid crystal display device of  claim 13 , wherein the particular transmittance is between 10% and 40%. 
   
   
       15 . The liquid crystal display device of  claim 13 , wherein the particular wavelength range is between blue light wavelength range and green light wavelength range. 
   
   
       16 . The liquid crystal display device of  claim 15 , wherein the particular wavelength range is substantially between 473 nm and 523 nm 
   
   
       17 . The liquid crystal display device of  claim 13 , wherein the particular wavelength range is between green light wavelength range and red light wavelength range. 
   
   
       18 . The liquid crystal display device of  claim 17 , wherein the particular wavelength range is substantially between 565 nm and 615 nm. 
   
   
       19 . The liquid crystal display device of  claim 13 , wherein the back light unit comprises a light guide plate disposed inside the housing, the at least one light generator is disposed on at least one side of the light guide plate, and the light guide plate has an incident plane where the white light beams enter and an exiting plane where the white light beams exit. 
   
   
       20 . The liquid crystal display device of  claim 19 , wherein the optical filter is disposed on the incident plane of the light guide plate. 
   
   
       21 . The liquid crystal display device of  claim 19 , wherein the optical filter is disposed on the exiting plane of the light guide plate. 
   
   
       22 . The liquid crystal display device of  claim 13 , wherein the at least one light generator disposed right below the liquid crystal display panel. 
   
   
       23 . The liquid crystal display device of  claim 13 , further comprising a diffusion device in between the back light unit and the liquid crystal display panel. 
   
   
       24 . The liquid crystal display device of  claim 23 , wherein the optical filter is disposed inside the diffusion device. 
   
   
       25 . The liquid crystal display device of  claim 23 , wherein the optical device is disposed in between the diffusion device and the liquid crystal display panel. 
   
   
       26 . The liquid crystal display device of  claim 13 , wherein the light generator comprises a fluorescent lamp. 
   
   
       27 . The liquid crystal display device of  claim 13 , wherein the light generator comprises a light emitting diode device. 
   
   
       28 . The liquid crystal display device of  claim 27 , wherein the light emitting diode device comprises an encapsulated layer, and the optical filter is integrated into the encapsulated layer of the light emitting diode device. 
   
   
       29 . The liquid crystal display device of  claim 13 , wherein the white light beams generated by the light generator go through the optical filter before going through the color filter. 
   
   
       30 . The liquid crystal display device of  claim 29 , wherein the white light beams remain white after going through the optical filter, and the white light beams are divided into light beams with different primary colors after going through the color filter.